As recently as the 1950's, double walled spherical tanks 100, illustrated in FIG. 1, were used for cryogenic liquid storage. These double walled spherical tanks 100 were supported on tubular carbon steel legs 102. The double walled spherical tanks 100 were typically ten feet to fifteen feet in diameter and comprising an inner stainless steel welded shell 104 and an outer carbon steel welded shell 106. The bottom third of the void space between the inner stainless steel welded shell 104 and the outer carbon steel welded shell 106 was filled with cellular glass blocks 108 and the remainder was filled with a perlite insulation material 110. The tubular carbon steel legs 102 were supported by a concrete foundation 112 on grade 114 and fastened to the concrete foundation 112 using an anchor bolt assembly 116.